Internal-combustion engine



April s. R. ERICSON 2,373,302

I INTERNAL-COMBUSTION ENGINE I Filed Dec. 10, 1942 2 Sheets-Sheet 1 7INVENT I i GERGE R. REGSQ .aa,

April ,1 e. R. ERlCSON 9 9 INTERikAL-COMBUSTION ENGINE Filed Dec. 10,1942 2 sheets-sheet 2 ATTORNEY -?atented W, 1945 STATESINTERNAL-COMBUSTION ENGINE George R. Ericson, Kirkwood, Mo., assignorto" Carter Carburetor Corporation, St. Louis, Mo., a corporation ofDelaware Application December 10, 1942, Serial No. 468,564

l3 Claims.

This invention relates to internal combustion engines and particularlyto automotive engine's of the multi-cylinder type The invention is, insome respects, an improvement of the invention shown-in my earlier filedapplication, Serial No. 453,116, filed July 31, 1942. Indevices of thecharacter shown in the previous application, the

fuel is cut off from some or all of the cylinders in accordance with thepower requirements of the engine as indicated by the vacuum in theintake manifold. The fuel cutoff is accomplished by a vacuum controlvalve in the fuel passage. Where the carburetor is of the plain tubetype having a fuel system comprising a plurality of outlets receivingfuel from a single inlet, the most con venient place for the cut-offvalve is at the fuel inlet. This is particularly true in' cases wherethe invention is to be applied in the field to an engine which isalready equipped with a carburetor, and where the only changes which canconveniently be made are those which involve nothing more than theaddition or substitution of parts without the necessit for doing anydrill ing or other machine work on the carburetor or engine. Wherethefuel is cut off at the inlet of the branched fuel passage, therenecessarily remains a small quantity of fuel in the passage posterior tothe valve. After the valve is shut off, the application of suction to.the idle passage in the normal operation of the engine drains the fuelsystems posterior to the cut-off valve, thus -reference to the followingdescription and accompanying drawings, referring to which:

-, ,Figure 1. is a diagrammatic view of a multi- I cylinder internalcombustion engine having my' invention applied thereto.

Figure 2 is a sectional elevation showing a carburetor equipped forthe'performance of my invention.

Figure 3 is a diagrammatic sectional view I taken alongthe' line 3-3 ofFigure 2.

pring.

wastin a small quantity of gasoline. Of course,

the quantity in the fuel passages may be very small, but the operationis repeated so often as f to involve noticeable waste of fuel over aperiod of time.

While the loss of fuel in the manner above described might bedisregarded, a slight lag in ac- 'celeration may occur, due to-the factthat when the throttle is open, it is necessary to refill the fuelsystem before any discharge can, be had into the mixing conduit. Thecut-off valve is instantly opened on account of the loss of vacuum assoon as the'throttle is opened, but it takes a noticeable amount oftimefor the suction of the car-. buretor to refill the fuel passages.acceleration may be substantially eliminated by withdrawing the fuelfrom the passages when the valve is cut off and returning it to refillthe passages when the engine is again accelerated.

It is an object of my invention to prevent the 'waste of the fuelcontained in the fuel system posterior tothe' cut-oil valve. It is afurther object of my invention to prevent the lag in acceleration causedby the neces- This lag in Figure 4 is an elevation of the device shownin Figures 2 and 3'with parts broken away and others shown in sectionalong the line ldof.

Figure 2. I

Figure 5 is a detail assembly viewshowing one of the metering rods orcontrol valves'together with its operating means and connections.

Figure 6 is a detail view showing the coasting- Figurel shows amulti-cylinde r internal cornbustion engine having eight cylindersnumbered I to 8. The engine block is indicated generally by thereference character 9, and this is connected to intake manifolds l0 andII which are served with fuel mixture by a carburetor l2 having twobarrels l3 and I4; Each barrel of the carburetor is supplied with fuelfrom the float-chamber i5 by-means of separate fuel passages l6 and I1,and the fuel supply to each passage is controlled by metering rods orvalves 18 and I9, respectively.

Main jets 20 and 2| are provided with restricted orifices forming valveseats to receive the cooperating valve portions of the metering rodsunder certain conditions hereafter described.

It will be understood that the barrels of the canburetor maybesubstantially the same in construction, and each comprises an airinlet.22, one

or more venturis 23, a main fuel, nozzle 2%, an

idle fuel nozzle25, and a throttle valve 26, which ismounted on shaft 21controlling the fuel dis-- charge outlet. 28. The carburetor is boltedonto the intake manifolds by means of the flange 29.

-' orries either open or. closed and not regulated.

controlling thejdischarge outlet of one of the with fuel from thejets'lll and 21. through passages 3|, which are connected to thepassages l8 and II, respectively, at a point between the main jet andthe discharge outlet of the main jet. It will beunderstoodthattheidlefuel may be supplied independently from the main jets, ifdesired, as shown in my prior Patent No. 1,967,708, issued June 5, 1934.Since'the present construction is intended for application in the field,as well as for original equipment, I have shown an existing type of.ca'rburetor which is provided with idle passages, discharge ports, andadjusting screws for both barrels of the carburetor. .In order to,

apply the invention, one of the idling screws 30 is removed and replacedby the pipe fitting -30l An idling adjustment screw 3'. is provided fer"with a valve portion 4: similar to the valve u,

' idling passages.- -The idle passages are supplied which maybe seatedtoshut off the fuel from the main jet 2| by furtheFdownwax-d movement ofthe piston 34 after the valve 39 has seated. The spring 38 is calibratedto permit the seating of the valve .43 when the suction exceeds thenormal idling suction, for instance, when coasting at speeds higher thanthe normal idling speed of the engine. I

One of the important features of this device is the provision ofmeansfor preventing the valves 39 and 43 iromoccupying a position in whichthey substantially restrict but do not completely close the jet, and Ihave provided special means for this purpose, as follows:

A magnet 54 is mounted on the rod in such a position that its lower endapproaches contact with the top of the jet just at the time when theand'the-connectin'g passage ili2'between the low' sity ofdrilling holesin the caiiburetor or manifold.

The above construction is fairly well known (except as indicated), andis frequently referred to as the plain tube type of carburetor. Theconstruction is such that when the throttle valve is in nearly closedposition, only fuel from the idle ports 25 is delivered to the engine,and when the throttle is opened, the fuel discharge is transthe mainnozzle prevents the discharge of fuel at the outlet 25, it beingunderstood that the venturis 23 cause a higher suction to be establishedat theoutlet of the main nozzle than that which exists at 25 during openthrottle operation.

The metering rods i8 and I! are connected to a pin 32 which is mounted.on piston rod 33.

This rod is connected to the piston 34 mounted in cylinder 35 foroperation by suction through the passage 36. This suction passage isconnected to the discharge outlet of the carburetor posterior to thethrottle, as at 81. A spring 38 is mounted under the piston in aposition to be compressed when the suction is high, so as to draw themembers l8 and i9 down into the main Jets. The

I metering rod 18' is provided with a valve portion 39, which seats inthe main jet 20, to cut oil all ma supply to the carburetor barrel l3and the inside manifold l when the suction is high. The point at whichthis main jet is cut off may be at a suction correspondingto to ofmercury, depending on the particular installation, and at low suction-sthe fuel is permitted to flow normally; subject to regulation by thegraduated metering portion 40 carried at the lower end of the rod 18. Insome installations, I replace the main jet with one slightly smaller andomit the graduated portion 40, so that the member 39 merely acts as avalve to control the lot which is The rod [8 isIconne-cted withthe pinby means of a limited, lost motion-flexible connection 4| which may beprovided with a light spring 42 to insure the firm seating of the valve39 without preventing further downward movement of the rods 33 and". Therod I9 is provided valve reaches closing position. The jet is made ofmagnetic material, so that the magnet holds the jet firmly to the seatalthough with a very light .pressure. The spring 42' is a very lightspring, just suihcient to hold the weight of the rod and valve againstthe slight suction normally present which draws the metering rod portion4|! of thevalve downwardly, but as soon as the magnet approaches thejet, the additional force or the magnet causes the valve to close with asnap action, which is only overcome when some substantial force isapplied by the spring 38 or by the manually operated member 49. However,as

. ferred to the main nozzle 24, and the suction from of the suctionitself. During normal operation, with the valve open, the normal suctionof the.

soon as the valve is broken away from its seat,

the magnetic action is weakened, and the valve opens with a snap action.This arrangement prevents the valve occupying a position in which itwould allow' a highly restricted flow of fuel through the jet but stillnot sufllcient to permit v operation of the cylinders. If the valveremained in such nearly closed position, it would simply resultin thewastage of fuel.

Another means for preventingthe valve from occupying a nearly'closedposition is the action carburetor can act on the metering rod portiononly, but the diameter and area of this portion are small compared tothe diameter and area of the valve member 39. Thus, when the valvemember begins to restrict the'fiow, the

downward force exerted on it is increased in the 4 measure of thedifference in area between the rod portion 40 and the valve member 39,and this In many installations, the action of the spring 38 maybe usedalone to oppose thev suction action and position the metering rods andthe valves 39 and 43. However, in some installations, thepositive'opening and closing of the valves will be improved by the useof the precompressed spring 55, which is held in a capsule composed oftop and bottom washers 56 held together by the rivet 51 which limits theexpansion of the precompressed spring 55, but does not preventcompression. The use of the spring 55 permits comparatively rapiddownward movement of the metering rod after-the establishment of apredetermined suction.- Also, the action of this capsule is to present afairly solid'bottom for the piston 34 during the normal idling period.

-. a'svasoa The valve 39 is designed to shut ofi its jet atapproximately winches of mercury of vacuum alone, while the valve 43 isnot intended to shut ofi its jet until a vacuum of at least 18 inches ofmercury is developed. With this wide differe'nce required in the actionof the valves, it would be necessary to provide for substantial travelof the piston 34 and corresponding extra length of 1 the metering rodportions 40, if the spring 38 alone were depended on to control theactuation of the valves. The provision of the spring capsule E6 permitsthe piston 34 to reach a definite limit of travel responsive to anyvacuum between 10 inches and 18 inches of mercury. This position isretained until the 18 inches isexceeded, at

which point the spring 55 yields and permits closing of the valve t3.

By this construction, the action of the parts may be more accuratelycontrolled, and the size and length of theparts may be reduced. It willbe understood that the figures of 10 inches and 18 inches of mercury areonly illustrative and may be varied substantially according to the re-'quirements ,of the particular engine and the use.

to which the device is applied. Without making any attempt to list thefactors on which the closing pressures of the valves will depend, it maybe noted that the compression ratio of the engine is an important factorin determining the normal idling manifold vacuum.

It will be understood that the usual accelerating pump is provided, andthat the pump discharge to the inside carburetor I3 is made a littleheavier thanto the outside carburetor, because thmanifold It will mostfrequently become dry and will require more fuel to wet it uponacceleratlon. The outside manifold is longer and has more surface towet, but the wetting action is initiated sooner after coasting, and iskept wet during normal idling.

- It will also be understood that the fuel may be first shut ofi in theoutside manifold ll while permitting the engine to idle on the insidemanifold it, but, in most'constructions, the shut ofi of the fuel to theinside manifold would be preferred on the ground that the manifold isshorter, has less well surface and capacity and, therefore, requiresless time and fuel to set it in operation after idling. h

The throttle shaft 2? is normally biased to close the throttle by theconventional spring starter switch is operated. It may. also be notedthrottle.

' It will be understood that the usual accelerating pump actuated byopening movement of the throttle is provided. An example of this pumpmay be found in my previous patent above mentioned, butit is notbelieved necessary to describe it in detail. A conventional automaticchoke mechanism is also provided, but this is not essential to thepresent invention and need not be described.

While the-automatic choke mechanism is not described in detail,reference may be had to cosey Patent No. 2,085,351, issued June 29,

1937, or Blattner Patent. No. 2,166,899, issued July 18, 1939, whichshows means for preventing the closing of the throttle to its full idleposition by the throttle spring, which is provided. to normally'maintainit in that position. This means operates during warmingup period, sothat the starting and warming up is accomplished by joint action of allth cylinders of the engine, and it should be noted that the adjustmentof the arm 60 with respect to the member as is such as to prevent theclosing of the valve 39 when the fast idle is in'operation; that is tosay, when the -throttle is held in the fast idle position, as by meanscorresponding to the members til-t i--% of the Coffey patent, or 32,etc., of'Blattner, the i throttle is opened far enough to insure thelifting generally that the link I26 shown in Figure 2 of thisapplication corresponds generally to the link 26 0f Coffey 2,085,351,and t0 link32 Of Blattner,

and the housing M2 and thermostatic control mechanism may be said tocorrespond generally to the housing as and thermo-control mechaiiim ofthe Cofiey patent.

From the foregoing, it will be observed that the present invention maybe adopted in carburetors of various types, particularly where the fueloils tributing system includes a manifold so constructed and arranged asto feed the explosive mixture to separate banks of cylinders from awhich is not shown. The shaft 21 is connected by means r the lever st,link as, and lever as to therockshait M.- This rock shaft carries alever so having a projecting arm #9 which is constructed and arranged tocontact thunderside of the horizontal projection 5B which is preferablyintegral with the upper end of the piston rod 33. The member .hasupturned lugs 5! (Figure 3) on which the pin. 32 is mounted, so as tomake a direct operating connection between the piston 3t and themetering rods is and It. This connection, however, is flexible by reasonof the fact that the spring 42 is bent at its ends to pass through theopenings 52 which are controlled through the metering rod above andbelow the slot or lost motion connection tl. The

connection between the throttle valve and projecting arm eels such thatthe projection is and the meteringrods are forced upwardly upon -anopening movement oi the throttle, and, in the preferredconstruction,'the rod 19 is firstlifted.

of! its seat to initiate the supply of fuel to the outside manifold M,and the-rod i8 is forced on" carburetor mechanism. In such assemblies,it will be practical with the present invention to permit the idling ofa motor only with an ex tremely small amount of power such as may bederived from an idling mixture supplied to only a part of th totalnumber of cylinders of the engine. This development is elastic, at leastto theextent that one or more jets can be totally closed where only alimited amount of power may be necessary to drive along a' substantiallylevel road at'a relatively limited speed. The closing of a jet, or ofmore than one jet, is essentially synchronized with the mechanismcontrolling the normal operation of the engine, and it is preferablethat the closing of the jet or jets be brought about with a snap actionsuch as will tend to eliminate undesirable and irregular explosionstending to bring about a possible surging condition in the motor.

. The greater part of the above subject matter is disclosedin mycopending application, Serial 'No.

453,116, flied July 31; 1942. I have found that the construction can befurther improved by the provision ormeans for withdrawingthe iuel from.

his seat later in the opening movement of the the fuel passages of thecarburetor between the cut-off valve and the discharge outlet. This fuelwithdrawing means is preferably constructed and arranged to operate bysuction, so as to withdraw the fuel at the time the fuel supply is cutoff and to return it as soon as the fuel supply valve is again opened.

A convenient means for applying this invention to a carburetor in thefield is embodied in the structure shown in Figure 3. The idling screwof the barrel of the carburetor, to which the fuel supply is controlledby the valve 39, is removed and replaced by the pipe fitting 3M, and aplug is placed in the passage 302, so that the full manifold suction isapplied to the pipe fitting. From this fitting, the suction is conveyedthrough a pipe 303 to a connecting member 304 at the end of cylinder305,,which contains a double piston 306-normally held in the positionshown by the spring 301. l The travel of the piston is adjustable bymeans of the screw 308 which is held in adjustable position by lock nut309. The cylinder 305 is threaded, as at 3l0, to screw into the openingflitt'hebase of the main nozzle 24 at the bottom of t ie'r ei well 3| I.i The piston 306 is constructed and arranged to closes, so thatsimultaneously with the closing of the valve, the piston is withdrawnagainst the pring 301. Since the connection 3H1 is at the the fuel fromthese passages through the port 25,

" which would otherwise occur as soon as the valve 39 is closed,it'being noted that the upper part of the well 3| l is provided with theair passage 3l2,

aslo other air bleeds above the fuel level l ZDllld permit the dischargeof the fuel contained 4 the passages, even after the valve 39 is closed.

pen acceleration of the engine, the fuel which has been withdrawn intothe cylinder 305 is immediately replaced, due tothe return of the piston306.

In order to obtain the greatest possible speed in the resumption ofnormal functioning by the nozzle 24 whenfuel feeding is resumed afterbeing cut off I provide a restricted passage 320 in the connection 3l0between the nozzle base or well l'|--3|l and the upper end of thecylinder 385. This passage is axially aligned with the passagewaythrough the nozzle 24 in such a manher as to direct a jet of fuel upthrough the nozzle base so as to produce an injector action to assist inrefilling the nozzle and restarting the fuel flow therethrough. Theaction of this jet may continue from one to five seconds so that thereis a continuous tendency to produce flow through the a nozzle wheneverthe suction drops sufliciently to permit the spring 301 to shift thepiston 30 6 to the position shown in- Fig. 3.

It might be supposed that leaving-the outlet of the: snatcher pump wideopen and unrestricted would. result in a quicker refilling of thenozzle, but tests show that the cylinders supplied by the nozzle 24resume operation more quickly and smoothly when the restrictedpassageway 320,

{respond to the same vacuumat which the valve,

Details of structure in which the valve 39 or its equivalent isinterconnected with the piston 308 are shown in copending applicationSerial No. 453,116, filed July 31, 1942.

Iclaim:

1. In an internal combustion engine, passage means for liquid fuelsupply, valve means controlled in accordance with the power demand onthe engine for cutting off said passage means, means for withdrawingfuel from the passage means when said valve means is closed, and

. means for restoring said fuel to the passage means when said valvemeans is again opened. 2. In an internal combustion engine having anintake manifold, a carburetor for supplying fuel to said manifold, saidcarburetor having a fuel passage, a valve for controlling said fuelpassage, means responsive to manifold vacuum for. controlling saidvalve, and means connected to said passage at a point posterior to saidvalve for withdrawing fuel when said valve is cut off.

3. In an internal combustion engine having an intake manifold, acarburetor for supplying fuel to said manifold, said carburetor havinga, fuel passage, a valve for controlling said fuel passage, meansresponsive to manifold vacuum for controlling said valve, meansconnected to said together with its injector action. are used instead ofan unrestricted passage at 320. This may be due in part to bettersynchronization between the I ll action of the valve 39 andthe action ofthe piston 306; but it has been. found that the restriction and injectoraction are still desirable even when the valves-39 and piston 306 areinterconnectedso as to positively insure simultaneous operation.

opened.

passage at a point posterior to said valve for withdrawing fuel whensaid valve is cut off, and means for restoring said fuel to. saidpassage when the valve is again opened. I

4. In an internal combustion engine having an intake manifold,acarburetor for supplying fuel to said manifold, said carburetor havin afuel passage, a valve for controlling said fuel passage, meansresponsive to manifold vacuum for controlling said valve, meansconnected to said passage at a point posterior to said valve forwithdrawing fuel when said valve is cut off, and means for deliveringsaid fuel to the fuel supply system of the engine when said valve isagain 5. In an internal combustion engine having an intake passage, .acarburetor, a throttle for cona trolling the flow of mixture from saidcarburetor to said engine, said carburetor having a fuel passageway,valve means for controlling said fuel passageway, means connected tosaid fuel passageway posterior to the valve for withdrawing fueltherefrom, and means operated by the manifold vacuum for controllingsaid valve and said fuel withdrawing means.

6. In an internal combustion engine having an intake passage, acarburetor, a throttle for controlling the flow of mixture from saidcarburetor to said engine, said carburetor having a fuel passageway,valve means for controlling said fuel passageway, means connected tosaid fuel passageway posterior to the valve for withdrawin fueltherefrom,- means operated by the manifold vacuum for controllingsaidvalve and said fuel withdrawing means and 'means controlled by saidthrottle for overruling said vacuum controlled means. 7. In amulti-cylinder internal combustion engine, separate intake conduitsleading to separate cylinders of the engine, fuel supply means for saidintake'conduits, valve means for cutting off the supply of fuel from'oneof said'fuel supply means, means connected to said fuel supply means ata point posterior to said valve for withdrawing fuel therefrom when thevalve is cut off,

. said means being constructed and arranged to return the fuel theretowhen said valve is again" opened.

8. In a mu1ti-cylinder internal combustion engine, separate intakeconduits leading to separate cylinders of the engine, fuel supply meansfor said intake conduits, valve means forcutting off the supply of fuelfrom one of said fuel supply means, means connected to said fuel supplymeans at a point posterior to said valve for withdrawing fuel therefromwhen the valve is cut off, said means being constructed and arranged toreturn the fuel thereto when said valve is again opened, and meanscontrolled by the vacuum in one of said intake conduits for controllingsaid valve.

9. In a multi-cylinder internal combustion engine, separate intakeconduits leading to separate cylinders of the engine, fuel supply meansfor said intake conduits, valvemeans for cutting ofi the supply of fuelfrom one of said fuel supply means, means connected to said fuel supplymeans at a point posterior to said valve for withdrawing fuel therefromwhen the valve is cut off, said means being constructed and arranged toreturn the fuel thereto when said valve is again opened, meanscontrolled by the vacuum in one of said intake conduits for controllingsaid valve, and manual means for overruling said vacuum means.

10. In a fuel supply device for internal combustion engines, meansforming a mixing conduit, means forming a fuel supply chamber, a passageleading from said fuel supply chamber to said mixing conduit, anexpansible chamber connected to said passage, means forming amovablewall for said expansible chamber, said movable wall having positionscorresponding to complete expansion and complete contraction 11. In afuel supply device for internal combustion engines, -means forming amixing conduit, means forming a fuel supply chamber, a passage forconveying fuel from said fuel supply chamber to said mixing conduit,snap action valve means for opening and closing saidpassage to cut offor reestablish flow of fuel'therethrough, and auxiliary meanssynchronized with said valve action for assisting the reestablishment offuel flow through'said passage when said valve is opened.

12. In a fuel supply device tion engines, means forminga mixing conduit,

,means forming a fuel supply chamber, a passage for conveying fuel fromsaid fuel supply chamber to said mixing conduit, snap action valve meansfor opening and closing said passage to cut off or reestablish flow offuel therethrough,

auxiliary means synchronized with said valve action for assisting thereestablishment of fuel flow through said, passage when said valve isopened and for assisting the abrupt termination of fuel flow throughsaid passage when said valve is closed.

13. In an internal combustion engine, a mix- Y at an angle from thelower part of said reserof said chamber, valve means for controlling theposition.

voir into said conduit, a metering orifice element in said passage, Iacylinder projecting from the bottom ofsaid reservoir in line with saidpassage and communicating with said passage posterior to said orificeelement, a piston in said cylinder,

spring means normally holding said piston at the upper end of saidcylinder, and a vacuum connection from the lower end of said cylinder tosaid conduit, said cylinder and piston being constructed and arranged towithdraw fuel from said fuel passage when high suction exists in saidcon duit and to return said fuel when the suction drops in said conduit.

GEORGE R. ERICSON.

for internal combus-

